Wireless telecommunication networks are designed for convenient data exchange between devices. Communication between one device and another in the network occurs across a wireless link, where the transmitting device or transmitter emits certain electromagnetic signals from its antenna which propagate over the wireless link and are picked up by the antenna of the receiving device or receiver. Communication devices may be used nowadays to locate or detect an object such as for instance a shop, a car, a monument, a person etc. . . . In some situations, communication devices may be used to detect the position of an object such as assisted car-park devices. Such devices use signals reflecting on the obstacle to detect it or determine the distance between the obstacle and the parking car. In the case of emergency situations such as major earthquakes or snow avalanches, persons may be trapped inside buildings or under rubble or snow and unable to escape. Clearly, time is of the essence in rescuing these persons since they may have serious injuries, lack of air, food and water, be exposed to extreme weather conditions and subject to further dangers such as falling rubble, fires, snow and so on. Conventionally, rescue services attempt to find these persons using infra-red cameras to detect body heat. However, this requires the use of trained personnel with expensive professional equipment in the case of human body detection, which is not readily available in most locations at short notice. Similarly, an embedded device that is dedicated to obstacle detection is required for instance for car-park assistance. In these cases, the device is not part of a public telecommunication network and a telecommunication network device such as a user equipment may not be commonly used to detect an object.
An existing solution described in “A Compact Low-Cost Add-On Module for Doppler Radar Sensing of Vital Signs using a Wireless Communications Terminal”, V. Lubecke et al, 2002, proposes a passive free-standing module that can be used in combination with an arbitrary telecommunications device for micro-Doppler sensing (i.e. detection). The module uses the transmitted signals from the telecommunications device as an “illuminator of opportunity”, and mixes both the direct signal and Doppler-shifted signal to produce the Doppler frequency. Communication of detected signals (i.e. detection of vital signs) is performed separately by the free-standing module. Drawbacks of this solution are that, as the module is dedicated and independent from the device, the module is not integrated in a telecommunication network nor embedded on a communication device. This solution prevents thus the user equipment to take advantage of the existing infrastructures and resources of a telecommunication network to perform the detection of a given object with a given profile.
Another existing solution described in “Wireless IC Doppler Radars for Sensing of Heart and Respiration Activity”, O. Boric-Lubecke et al, 2003, proposes detection of heart and respiration activity with micro-Doppler using a sensor constructed from components designed for telecommunications devices rather than a custom radar system. However, in this solution, the specificity of the telecommunication system is not taken into account, such as in particular the resource allocation. This sensor solution cannot be adapted to a user equipment in a telecommunication network and prevents thus the user equipment to take advantage of the existing infrastructures and resources of a telecommunication network to perform the detection of a given object with a given profile.
Another existing solution described in U.S. Pat. No. 6,700,528 B2 “Motion Detection and Alerting System”, C. Williams, 2004, proposes a motion detection device using Doppler comprising a low cost radar IC, battery, and separate mobile phone device for communications. Drawbacks are that the solution prevents the user equipment to take advantage of the existing infrastructures and resources of a telecommunication network to perform the detection of a given object with a given profile.
Another existing solution described in WIPO patent application WO 2007/136610 A2 “Determining Presence and/or Physiological Motion of One or More Subjects with Multiple Receiver Doppler Radar Systems”, O. Boric-Lubecke et al, 2007, proposes the use of multiple radar receivers for motion detection using Doppler (this is well-known in the literature as multistatic radar). The novelty is mostly regarding a blind source separation (BSS) signal processing technique (e.g. for separation of Doppler signals from multiple persons) and demodulation techniques. This solution prevents thus the user equipment to take advantage of the existing infrastructures and resources of a telecommunication network to perform the detection of a given object with a given profile.
Today there is no solution to efficiently detect objects that allow using common devices in wireless telecommunication systems and thus improving the functionality of such wireless telecommunication systems.
Therefore, there is a need for a device, of which one or several might be present in an average home, office, vehicle or mountain environment, which is capable of independently detecting the presence of objects such as e.g. persons in its local vicinity and reporting this fact to a user or rescue services or other volunteers who then have the opportunity to save these persons as quickly as possible. Today there is a need for an object detection solution that can be easily implemented on the existing communication infrastructures.